One way or another, the U.S. business community is bent on delivering India Prime Minister Manmohan Singh a message when he visits the White House on Friday: Stop the protectionism.

President Barack Obama and Singh are expected to discuss ways to revive an economic relationship rife with complex and long-standing problems but lacking in clear solutions – especially under the stress of the global downturn — when they meet in a few days.

But confronting Singh as soon as he steps off the plane at Dulles International Airport will be advertisements underscoring just how frustrated American businesses have become. They’ve been placed on the airport’s walls as well as in the pages of The Washington Post, The Wall Street Journal and other Capitol Hill newspapers, and on the top of several media outlets’ websites by the National Association of Manufacturers.

The policies the American businesses are targeting include India’s “buy local” manufacturing rules, the country’s limits on foreign investments in industries ranging from insurance to supermarkets, and its moves to revoke U.S. drugmakers’ pharmaceutical patents. As a result of these obstacles, American businesses have all but given up on entering the India market.

“Their brand has been rather devastated for U.S. investments,” said Linda Menghetti Dempsey, the National Association of Manufacturers’ vice president of international economic affairs.

The business lobby’s frustration is fueled by a desire to tap into what it sees as vast, untapped potential. India’s population of 1.2 billion and its growing middle class represent a massive market – and it already shares a crucial geopolitical relationship with the United States.

Yet the two countries’ trade statistics don’t measure up to their status as the world’s largest democracies. India is just the United States’ 13th-largest trading partner – and the $22 billion in U.S. exports there last year pale in comparison to the $110 billion in U.S. exports to China. Trade between the United States and India has ticked upward this year, but only marginally so.

The Obama administration has pushed to improve those numbers, dispatching Secretary of State John Kerry to New Delhi in June and Vice President Joe Biden there in July.

Those visits have yielded several quick – but limited – results.

In July, India hit the brakes on its plans to mandate that telecommunications companies use only domestically manufactured equipment and the country’s Ministry of Finance announced a weekly meeting where companies seeking entry into India’s market can get explanations of complex tax rules.

Then, in August, India relaxed its “multi-brand retail” policies, opening the door for major retailers like Wal-Mart to own up to 51 percent of supermarkets there.

And last week, the Ministry of Finance issued new rules establishing a safe harbor that allows multinational companies to avoid being taxed in India for work done in another country.

India, which is grappling with burgeoning power demands, this month is also rapidly working to revive a stalled 2008 deal that would open the door to contract with U.S. companies capable of building nuclear reactors there. Progress was slowed after the Indian government announced regulations that pin all the liability on the companies that supply the equipment in the case of incidents or meltdowns, which caused U.S. businesses to balk at taking on such a potentially costly role. Those rules have since been relaxed, and the Indian government is working frantically to put the finishing touches on a deal with U.S. nuclear supplier Westinghouse Electric Corp. that would have the company go forward with some of its preliminary work in the state of Gujarat.

“None of these are clear, grand-slam, home-run wins. Nonetheless, to say India hasn’t reacted at all wouldn’t be exactly true,” said Richard Rossow, the South Asia director for McLarty Associates, a Washington, D.C.-based trade consulting firm.

Despite India’s moves, members of Congress are expressing growing interest – and agitation – over the struggles U.S. businesses are having as they attempt to enter the country’s market.

The House Ways and Means Committee and Senate Finance Committee tasked the U.S. International Trade Commission in August with putting together a report by November 2014 detailing India’s policies that restrict trade, limit foreign investment and fail to honor intellectual property rights.

The Senate Banking Committee’s trade subcommittee, meanwhile, has scheduled a hearing for Wednesday where it, too, will delve into the issues that lock U.S. financial service providers out of India’s market.

And Rep. Lee Terry (R-Neb.) introduced a bill last week that would revoke India’s ability to export products to the United States free of tariffs through the Generalized System of Preferences program until the country scotches its preferences for local manufacturers, respects foreign pharmaceutical drugmakers’ patents and more.

“Trade preferences are not a gift,” Terry said.

India has demands of its own. It wants to capitalize on the U.S. natural gas boom by qualifying to receive exports from terminals the Department of Energy has started to approve. It also wants immigration reform talks to occur without the prospect of limiting the H-1B visas that Indian information technology firms could access to send their employees to the United States for short-term work. And it would like an agreement that would allow Social Security payments made by those workers to be credited to India’s home market, which could be tough since the country doesn’t have an equivalent system in place.

The best way to address the issues separating the United States and India could be through a bilateral investment treaty – but that’s a longshot.

Negotiations toward such a treaty started under President George W. Bush in 2008, but stalled out as the Obama administration reviewed its model language for those treaties, and then the Indian government launched a similar review of its own. The two countries held one meeting to discuss plans for the treaty, in 2012, but the momentum has largely stalled.

The kind of bilateral investment treaty that the United States would want – one that bans “buy local” mandates and eliminates caps on foreign investments – would require a culture change for India’s negotiators. Of its 72 existing treaties, only one – with Kuwait – bars “buy local,” and none address investment caps.

“It’s not going to be easy, but changing a relationship in a big way never is, and this is one thing that could really do it,” Rossow said.

Regardless of what the leaders discuss, it’s not clear how much can be done by Singh, since his tenure as prime minister is due to end no later than May 2014 and elections could sweep an opposition party into power.

Still, Dempsey sounded a hopeful note about the two leaders’ upcoming meeting. “The prime minister and the president can really put this relationship back on track and more towards a path where we grow economic opportunities,” she said.